If you want the IR effect go with a Hoya 720 nm filter (IIRC. this was the cheapest filter available. I think I went through ebay) and then you'll want to rate it really low. Basically the film is way more sensitive to red light than it is to infrared light so if you can see well through the filter you'll still be getting the deep red effect. I think I used ASA 1.5 with that filter with good results in TMAX developer. It's been a year or three though.

Both the Hoya R72 and the Cokin work well in my (limited) experience. It is worth studying the longish document that Efke posts about this film on their web site. If you want the IR "bloom" be sure to get the version of the film that has no anti-halation coating.

If you accept the manufacturer's rating of ISO 100 for the film, and add five stops for the infrared filter, you wind up with ISO 3. But 1.5 is probably better in most situations. In any case, bracket generously, since it is very difficult to assess how much infrared is actually there in any given scene.

Don't know where you plan to be shooting at this time of year, but generally there is more infrared in early morning or late afternoon, in spring or early summer. Another advantage of spring shooting is the little tiny leaves that are just busting out. Although these look green to the eye, they actually reflect tons of infrared, making for shots that look almost like snow scenes.

It's kind of unpredictable stuff, so just decide you're going to have fun experimenting!

I use a Chinese R72 (720nm lowpass) clone and EI1 in Sunny-16 conditions, i.e. 1s at f/16 in full sunlight. Gives some decent detail into deep shadows while still retaining printable and detailed highlights on sunlit foliage. That exposure is also good for backlit foliage.

Anybody ever tried these modern IR films in Diafine? I have some Rollei in the freezer, the R72 filter, and plan to give that a go this spring, mainly because there's no guess work about time and temperature, same for all films and it does what it's going to do. It gets a bit of extra speed from some films so we'll see if that helps with these films.

I have, with stunning results. 5 to 6 mins in Solution a and b. 30 secs agitation for the first min in both solutions and then 3 secs every 30 secs thereafter. Dump each solution quickly. No wash. Fix for 5 mins. Wash for 5 mins. Dry normally. I use a wash agent from the out fit in Wash state.... can't think of the name....also I prefer the Aura. I do mine in a Bronica ETRSI with a 40mm. Have fun !!!!!
Logan